21223020020 has 48 divisors (see below), whose sum is σ = 45438554448. Its totient is φ = 8323660800.

The previous prime is 21223020001. The next prime is 21223020041. The reversal of 21223020020 is 2002032212.

It can be written as a sum of positive squares in 8 ways, for example, as 3055215076 + 18167804944 = 55274^2 + 134788^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21223019977 and 21223020004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1903502 + ... + 1914618.

It is an arithmetic number, because the mean of its divisors is an integer number (946636551).

Almost surely, 2^21223020020 is an apocalyptic number.

21223020020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21223020020 is an abundant number, since it is smaller than the sum of its proper divisors (24215534428).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21223020020 is a wasteful number, since it uses less digits than its factorization.

21223020020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12980 (or 12978 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

Adding to 21223020020 its reverse (2002032212), we get a palindrome (23225052232).

The spelling of 21223020020 in words is "twenty-one billion, two hundred twenty-three million, twenty thousand, twenty".